Teeth, Beauty, Biology, and Health

I. A Universal Human Preoccupation

Looking good is a universal human preoccupation. We
acknowledge that our perception of beauty in people is
culturally derived when we say that 'beauty is in the eye of
the beholder.' Ornamentation seems to matter in the animal
kingdom where it is usually the male who is colorful; a
biological fact especially evident in birds. Decoration and
body shape matters in many human societies; tattooing, body
piercing, and dental mutilation has both a long history and
a world wide distribution. Every culture--at every time in
history--is/has been preoccupied with good looks.

Figure One. Culturally modified teeth

Are there cultural universals? When British researchers asked
women from England, China, and India to rate pictures of various
Greek men, their choices were identical. When asked to select a 'good
looking' face from a diverse collection, whites, Asians and Latinos
from 13 countries shared the same choices. Even infants have a sense
of what is attractive: 3- and 6-month-old infants will gaze longer at
an attractive face that one the is not attractive. Regardless of
nationality, age, or ethnic background, people universally share a
sense of what is attractive

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II. What is Attractive?

What, then, is beauty made of? We seem wired to find robust health
prettier than infirmity. All animals are attracted to other animals
that are healthy. Attractiveness seems to certify biological quality.
To my knowledge, for example, no culture considers rotting teeth and
body lesions as beauty aids. Having an attractive smile signals
biological health. Teeth make a crucial difference in how we look and
what hidden messages we convey

The single feature that matters time and again in animal
studies is symmetry. Insects, birds, and mammals prefer a
mate with symmetry and balance. The biological cost of
displaying that symmetry can be enormous: consider the
diagram of the Irish elk shown here.

Those antlers, shed annually, are a burden to carry and
consume enormous resources. Moose and elk illustrate that
symmetry is important, and in some situations, animals
engage in a sort of runaway arms race to display it. The
first feature of human attractiveness is symmetry.

Figure Two. The Irish Elk (Megaceros hibernicus)

A second feature in human attractiveness is averageness. A century
ago, Charles Galton, the eccentric cousin of Charles Darwin
superimposed the faces of many criminals seeking to find the
'criminal face type'. The result was something confirmed in many
subsequent studies: many faces assembled into a composite produce a
face better looking than those individuals.

Let me add one qualification: the faces we find most beautiful
have some exaggerated features. The most ideal female has a higher
forehead, fuller lips, an shorter jaw and a narrower chin. Men
particularly favor a waist-to-hips ratio of 7:10 The ideal male has a
big jaw, a broad chin and an imposing brow. Square-jawed males are
more likely to attain higher rank in the military. These choices seem
to apply cross-culturally: New Mexico, British, and Japanese students
express similar preferences.

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III. Benefits and Risks of Good Looks

Most symmetrical males have sex earlier (by three to four years)
and more often than their lopsided brethren. Greater symmetry also
predicted a larger number of past sex partners. Women with highly
symmetrical partners were more than twice as likely to climax during
sexual intercourse. Men with symmetrical bodies are typically larger
than their peers, more muscular, athletic and dominant in
personality.

Women are more sexually responsive to symmetrical men. Men who
have it exploit that advantage. Extremely symmetrical men are less
attentive to their partners and more likely to cheat on them. Women
show no such tendency. Our innate tendency to prefer symmetry
unfortunately doesn't prepare us to prefer integrity, personal worth,
or life in complex technological societies. Our beauty lust is better
suited to the Stone Age than an era of freeways and computers where
commitment matters more than ever before.

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IV. Beauty and Health; What Does Symmetry Tell About
Biology?

One genetic characteristic that symmetry reveals is genetic
diversity. Follow this closely: The more heterozygous the individual,
the more facial symmetry is observed. The ability to successfully
resist or withstand various environmental traumas or parasitic
infection. A heterozygous individual has a wider range of genetic
potential to resist parasitic invaders--to produce proteins that are
unfamiliar to infectious organisms. Pathogens are least resistant to
rare alleles.

A specific type of asymmetry called fluctuating asymmetry is
observed in teeth. It just means that teeth are larger on one side
than the other. Animal studies have shown that Selye stress produces
teeth of different sizes right and left (directional asymmetry) when
exposed to intense stress (such as immersion in ice water). A
biologically strong individual, whether a rat or human can better
withstand stress than a weak one. Fluctuating asymmetry correlates
with lower survival and growth rates, and fewer offspring.

One final observation: facial asymmetry may provide more
information when displayed by men than women.

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V. Mathematics, Proportion, and Esthetics

Can beauty be reduced to mathematics? Yes and no. Mostly
no. In art and architecture is a legendary old proportion
known variously as the golden proportion, golden section, or
as Fibonnaci Numbers. It is the proportion 1 to .618. The
proportion is considered pleasing to the eye and appears in
classical architecture and even in Khufu's tomb chamber
within the Great Pyramid, Giza, Egypt. In the diagram below,
Side A is to B as B is to the sum of A and B. Fibonacci
Numbers date from recreational mathematical games developed
in the 12th century.

Figure 3. The Golden Section

The golden proportion applies to the widths of upper
incisor teeth and to the lengths of the metacarpals in the
fingers.

Footnote on Fibonnaci numbers: They date from
recreational mathematical games devised in the
12th Century. If a golden section is drawn as in
figure three above is drawn and a perfect square is removed
from it, the remaining rectangle is also a golden section.
If this process is continued and circular arcs are drawn in
each perfect square so that they are continuous with one
aonther (as in figure three), a logarithmic spiral is
created. This form is found in nature as the whorls on a
pineapple or a pinecone. In botany, this phenomenon is known
as phyllotaxis.

Figure Four

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VI. Marquardt's Face Template

A California oral surgeon has devised a geometric face
template based on Fibonnaci Numbers to assess facial
symmetry and proportion. It has received publicity on Hard
Copy and the Discovery Channel, but has gained little
respect from the academic community. It is shown here as
something interesting and creative. The drawing of the face
of actress Audrey Hepburn is shown with an adaptation of
Marquardt's template superimposed to reveal facial symmetry
and proportion.